(feat) internal/civisibility: add Known Tests feature and refactor EFD logic

[tonyredondo]

What does this PR do?

This PR refactors the Early Flake Detection feature to stop depending on the test.is_new tag and introduces the Known Tests feature.

Motivation

RFC: https://docs.google.com/document/d/1mPMM7Uye2jHUMx5ADTMSRt_Rff98klRLj5OpTruszzQ/edit?tab=t.0

Reviewer's Checklist

• Changed code has unit tests for its functionality at or near 100% coverage.
• System-Tests covering this feature have been added and enabled with the va.b.c-dev version tag.
• There is a benchmark for any new code, or changes to existing code.
• If this interacts with the agent in a new way, a system test has been added.
• Add an appropriate team label so this PR gets put in the right place for the release notes.
• Non-trivial go.mod changes, e.g. adding new modules, are reviewed by @DataDog/dd-trace-go-guild.
• For internal contributors, a matching PR should be created to the v2-dev branch and reviewed by @DataDog/apm-go.

Unsure? Have a question? Request a review!

[datadog-datadog-prod-us1]

Datadog Report

Branch report: tony/civisibility-known-tests
Commit report: 76834db
Test service: dd-trace-go

✅ 0 Failed, 5222 Passed, 72 Skipped, 2m 11.81s Total Time

[pr-commenter]

Benchmarks

Benchmark execution time: 2025-02-03 21:58:46

Comparing candidate commit 1a9f6c2 in PR branch tony/civisibility-known-tests with baseline commit dbfb8f2 in branch main.

Found 0 performance improvements and 1 performance regressions! Performance is the same for 58 metrics, 0 unstable metrics.

scenario:BenchmarkPartialFlushing/Enabled-24

• 🟥 avgHeapInUse(Mb) [+1.769MB; +6.505MB] or [+2.579%; +9.484%]